SSH connection status indicators

- Add Connected bool field to vfs.Entry and RemoteMount
- Track connection status in sshState.connectedHosts
- Show status icon (connected/disconnected) in pane header when browsing remote host
- Async SSH connection test with cancel support for Add Host dialog
- Colored labels and styled help text in SSH dialogs
- Confirmation dialog when deleting manually-added SSH hosts

vendor/golang.org/x/sys/unix/ioctl_unsigned.go

@@ -6,9 +6,7 @@
 
 package unix
 
-import (
-	"unsafe"
-)
+import "unsafe"
 
 // ioctl itself should not be exposed directly, but additional get/set
 // functions for specific types are permissible.
@@ -28,6 +26,13 @@ func IoctlSetPointerInt(fd int, req uint, value int) error {
 	return ioctlPtr(fd, req, unsafe.Pointer(&v))
 }
 
+// IoctlSetString performs an ioctl operation which sets a string value
+// on fd, using the specified request number.
+func IoctlSetString(fd int, req uint, value string) error {
+	bs := append([]byte(value), 0)
+	return ioctlPtr(fd, req, unsafe.Pointer(&bs[0]))
+}
+
 // IoctlSetWinsize performs an ioctl on fd with a *Winsize argument.
 //
 // To change fd's window size, the req argument should be TIOCSWINSZ.